UNIT II Carotenoids and Xanthophylls General methods of structure ..
Flavonoids (or bioflavonoids ..
All reactions were performed under argon and monitored by TLC and analytical HPLC. Otherwise indicated, the 1H and 13C NMR spectra were recorded in CDCl3 with a Varian Gemini-300 spectrometer at 300 and 75 MHZ, respectively (proton decoupling mode for carbon). 1H NMR spectra were referenced to the signal at δ = 7.27 ppm of residual CHCl3. 13C NMR spectra were referenced to signals of CDCl3 (δ = 77.0 ppm). Resonances of the benzyl group are not mentioned. FT-IR spectra were recorded with a Nicolet Avatar 320 FT-IR spectrophotometer. UV-visible Spectra were recorded with a Kontron Uvikon 930 spectrophotometer fitted with a quartz cell.
General Properties of flavonoids Crystalline compound ..
General procedure for synthesis of Flavanones and Aryl chalcones by microwave: 2.5 mmole of Hetero Aldehyde/Aryl Aldehyde and 2.5 mmole of 2-hydroxy-4-substituted acetophenone were taken in 250ml RBF. 20 ml Ethanol and 0.1 mole of Potassium hydroxide were added in same RBF. The RBF was kept in Microwave at low voltage for 2-8 min. The reaction was moniterd by TLC. Ethanol was evaporated and solid washed with cold water. Recrystallized from Methanol.
Unit ii carotenoids and xanthophylls general ..
"Flavanones are chiral molecules, which come in two 'flavors,'" said Scheidt, who is left-handed and says he has been sensitive to handedness all his life. "We have a method to make just one 'flavor,' which no one has done before. Chiral molecules come in mirror images of the other, or two different 'hands.' Like your own hands, you can't superimpose one hand on the other. In both people and molecules, a left hand and a right hand are very similar but are not the same. In synthesizing flavonoids, you want to make one handedness over the other."